1. Field of the Invention
The present invention relates to a display device using a plasma display panel (PDP), and in particular to a plasma display panel in which an electromagnetic wave can be restricted that occurs when a drive voltage, such as a sustain voltage, is applied to a pair of display electrodes.
2. Related Arts
The focus is now on the use of plasma display panels (hereinafter referred to merely as PDPs) as a large screen full color display device. For a tri-electrode surface discharge type AC PDP especially, a plurality of display electrode pairs are formed to generate a surface discharge on a substrate near the display side, and address electrodes that intersect the display electrode pairs and a fluorescent layer for covering the electrodes are formed on a substrate on the rear side. To drive the PDP, basically, a large voltage is applied to the display electrode pairs to reset them, a discharge is performed between one electrode of the display electrode pair and an individual address electrode, a sustain voltage is applied between the display electrode pair, and a wall charge generated by the discharge is employed to generate a sustain discharge between the display electrodes.
FIG. 20 is a schematic diagram illustrating a conventional plasma display device. Display electrode pairs X1, Y1, X2 and Y2 are formed in parallel on a PDP 1. Address electrodes (not shown) are disposed perpendicular to the display electrode pairs. X electrodes are driven by a common drive circuit 2, and Y electrodes are driven by a Y electrode drive circuit 3, which can drive the Y electrodes independently. A sustain discharge voltage is applied to the X and Y electrodes to produce a sustain discharge.
Upon the application of the sustain discharge voltage, a charge is placed on a spacial capacitor between the X electrode and Y electrode. When a voltage exceeding a specific discharge voltage is generated between the electrodes, a sustain discharge occurs. Therefore, when the sustain discharge voltage is applied between the two electrodes, equally, current I flows to the two electrodes. The example in FIG. 20 shows the condition when the sustain discharge voltage is applied to the Y electrode by the Y electrode drive circuit 3. In this case, the X electrode is grounded.
In conventional plasma display device, the Y electrode drive circuit and the X electrode drive circuit are provided at either end of the panel 1. Thus, for example, a charge current that accompanies the application of the sustain voltage flows in one direction at one time, as is shown in FIG. 20. The sum of such a current flows in the opposite direction along the ground wiring between the two drive circuits. The sum of the current is very large, and even when the ground wiring has sufficient width and thickness, a very large electromagnetic wave is generated by passing the total current across an inductance L.sub.GND included in the ground wiring. Further, the X electrode and the Y electrode also have inductances L1 and L2. Their inductances L1, L2 are comparatively large, and even when a current I flowing across the individual electrodes is small, a comparatively large electromagnetic wave is produced.
An electromagnetic wave generated by a plasma display device is large at a frequency lower than a frequency of 30 MHz to 1 GHz, which is to be regulated. If the electromagnetic wave carries a great amount of energy, even though at a low frequency, this is undesirable because the erroneous operation of a peripheral device may result.
In addition, in the conventional plasma display device, a panel 1 on which display electrodes are formed is connected by a cable to external circuit boards on which mounted integrated circuits, including drive circuits. At one side of the panel 1 is provided a Y electrode drive circuit 3, which can independently drive the individual Y electrodes. In accordance with recent increases in size and more detailed fabrication, the pitches of the Y electrodes tend to be reduced and the density of the connection electrodes is increased to connect the Y electrodes to the drive circuits. As a result, it is difficult to provide wiring between integrated circuits (IC) in the Y electrode drive circuit and electrodes for the connection of the Y electrodes. The arrangement of the conventional drive circuits will not be suitable for further detailed fabrication.